A PHRED score is defined as -10*log(p) rounded to an integer,
where p is a probability.

To conserve space, the integer value of a PHRED score is encoded
as an ASCII character in fastq files. Unfortunately two encodings
have been used, one that increments the value by 33 and the other
by 64. Most fastq files use 33 and that is the default in this
module.

PHRED scores are integral, and it is unclear what convention is
used to convert the resulting float value to an integer. Thus,
the optional f is provided to dictate this. The default is to
round the computed score to the closest integer.RaisesError if x is not between 0.0 - 1.0.

The conversion produces a float, and it is unclear what
convention is used to convert the resulting float value to an
integer. As in Biocaml_phredScore.of_probability, the optional f parameter is
provided to dictate this.

The conversion produces a float, and it is unclear what
convention is used to convert the resulting float value to an
integer. As in Biocaml_phredScore.of_probability, the optional f parameter is
provided to dictate this.